While technically true, I think that's in tropical Africa. Are there also diseases that they carry in North America? Even without disease, I tend to agree with the OP that black flies are worse than mosquitoes, and don't think I've ever heard of anyone getting a disease from a black fly bite in the US or Canada.
You're mostly correct, but apparently not totally :) - I did think that it was further north, but the human cases are usually only in south and central america and africa.
Nonetheless, there are some.
